That's not a compression driver, no matter where you hang it in a horn? 
Ok here is a picture of a quickie set up of my ribbon. Mine is bigger and better than yours... nah nah naaa nah.
Coming next, after I download them, shots of of the inner guts of the phase plug on the 6681b!!
Ok here is a picture of a quickie set up of my ribbon. Mine is bigger and better than yours... nah nah naaa nah.
Coming next, after I download them, shots of of the inner guts of the phase plug on the 6681b!!
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Nice ribbon, commercial or homebrew?
may or may not be better... what's the reference sensitivity and impedance?
Seems to me that you could run ur 6681 down to that 150Hz point and get rid of yet another xover point, and/or run it up higher, like to 4kHz. The advantage to this is getting essentially the full "voice range" from a single source. In theory anyhow this would mean less phase shift, flatter response, and of course automatic "time alignment".
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may or may not be better... what's the reference sensitivity and impedance?
Seems to me that you could run ur 6681 down to that 150Hz point and get rid of yet another xover point, and/or run it up higher, like to 4kHz. The advantage to this is getting essentially the full "voice range" from a single source. In theory anyhow this would mean less phase shift, flatter response, and of course automatic "time alignment".
_-_-
The ones shown are Stage Accompany 8835, they do >100dB/1w/16ohms, and will do 128dB SPL <1%Thd. Bandpass is 1.5kHz to ~22kHz. As with most ribbons their main issue is lack of vertical HF dispersion. Other than that, very hard to beat in that frequency range.
But generally I don't like to have a crossover in the middle of the audio band if it is possible to avoid it.
But generally I don't like to have a crossover in the middle of the audio band if it is possible to avoid it.
I have always wondered if ist is a smaller magnet gap with monstreous magnets, or the ribbon speaker transformer that give the RAAL lazy ribbon and the Stage Accompany 8835 their high sensitivity. Do you know?
True ribbons sound probably fairly similar. My true ribbon is beaten below 5kHz by the TPL150 and by compression drivers in dynamics, I.e. powerfulness or being involving.
True ribbons sound probably fairly similar. My true ribbon is beaten below 5kHz by the TPL150 and by compression drivers in dynamics, I.e. powerfulness or being involving.
Yamaha 6681B Phase Plug SALTED
Don't store your compression drivers in the natural environment in Florida!! No, I don't live in Florida, but this one came from Florida. Yikes!!
Shown is the phase plug partially disassembled, from the side where the diaphragm installs (the back of the driver). Also the driver guts before the phaseplug was removed. The sound exits down in this image. The stuff all over the place is corrosion due to salt.
Don't store your compression drivers in the natural environment in Florida!! No, I don't live in Florida, but this one came from Florida. Yikes!!
Shown is the phase plug partially disassembled, from the side where the diaphragm installs (the back of the driver). Also the driver guts before the phaseplug was removed. The sound exits down in this image. The stuff all over the place is corrosion due to salt.
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The SA has no transformer.
The sensitivity comes from the flux in the gap.
And low moving mass.
A xfmr merely does impedance matching. Afaik.
The SA is a "leaf ribbon" meaning it is printed traces on a kapton substrate. Very thin. Aluminum traces.
SA uses massive blocks of neodymium magnets.
If you get within 8-10 inches with something magnetic and do not hold on to it, ur in trouble! It will get sucked in. Powerfully sucked in.
I actually think that one could focus more flux with the SA set up, but they probably figured that it was sufficient the way they did it.
Bear,
One of the guys I know designed the ribbon tweeter at I think they use the name Orca, and the amount of Neo magnet material would blow your mind. Then again at the price they wanted for those things so what! The moving mass is next to nothing when you think of the surface area of those devices. Wonder what one would sound like with a beryllium foil instead of aluminum or Kapton?
One of the guys I know designed the ribbon tweeter at I think they use the name Orca, and the amount of Neo magnet material would blow your mind. Then again at the price they wanted for those things so what! The moving mass is next to nothing when you think of the surface area of those devices. Wonder what one would sound like with a beryllium foil instead of aluminum or Kapton?
Orca was the USA part of Focal, afaik.
The equations for the ribbon tweeter show that the moving mass is a big deal, as I recall. Perhaps the biggest part of it. Which is why copper or silver is never used.
Beryllium foil does not have the requisite conductance.
The SA uses aluminum conductors on a kapton substrate.
So the conductivity is that of aluminum.
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The equations for the ribbon tweeter show that the moving mass is a big deal, as I recall. Perhaps the biggest part of it. Which is why copper or silver is never used.
Beryllium foil does not have the requisite conductance.
The SA uses aluminum conductors on a kapton substrate.
So the conductivity is that of aluminum.
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Bear,
Yes they are the Focal distributor and I know them, but they also developed their own ribbon tweeters and other systems under their own name. I'll have to look it up. So what about aluminum on a beryllium foil, don't see why that couldn't be done if that is the problem, But why wouldn't beryllium by itself work, it is used in beryllium copper contacts and other electronics? It is a conductive metal.
Yes they are the Focal distributor and I know them, but they also developed their own ribbon tweeters and other systems under their own name. I'll have to look it up. So what about aluminum on a beryllium foil, don't see why that couldn't be done if that is the problem, But why wouldn't beryllium by itself work, it is used in beryllium copper contacts and other electronics? It is a conductive metal.
Interesting. The Transmission Audio use pure aluminum foil, and they seem slightly thinner than household alu foil. Now that is light weight! It is likely that a true ribbon plays a little cleaner than kapton covered aluminum. The Beyma TPL-150 does not play as clean and it is copper covered with a kapton membrane.
See the picture called "1" MF_HF Ribbon unit" at http://www.transmissionaudio.com/ourribbons.html
Several of them in one of their speakers: http://www.gadgetguy.com.au/cms/wp-content/uploads/most-exclusive-av-transmission-audio-439x450.jpg
I also run mine transformerless, even tho they come with a transformer, but I use a homemade graphite-resistor not to completely fry my temporary solidstate amp. I reach 0.5 ohm. I think it sounds a little cleaner, but to achieve higher volume I should use the transformer. The graphite resistors can't withstand more than 5-10W before sounding scrubby. I have heard a ribbon speaker, like the Scintilla, need a vintage Krell amp to no distort.
The TA ribbon speaker uses very strong nedynium magnets, if I come 2 inches away from it anything metallic is drawn into it. But 8 inches away seem overkill! That is so strong it probably could cause health issues.
I would go at it with a dremel tool and be sure to tape over the magnetic gap. And later run tape into the magnet gap to remove particles. I bought a EL84 with a similar moisture issue. I used the dremel tool on every tube pin in the amp, and I got rid of a lot of noise.
See the picture called "1" MF_HF Ribbon unit" at http://www.transmissionaudio.com/ourribbons.html
Several of them in one of their speakers: http://www.gadgetguy.com.au/cms/wp-content/uploads/most-exclusive-av-transmission-audio-439x450.jpg
I also run mine transformerless, even tho they come with a transformer, but I use a homemade graphite-resistor not to completely fry my temporary solidstate amp. I reach 0.5 ohm. I think it sounds a little cleaner, but to achieve higher volume I should use the transformer. The graphite resistors can't withstand more than 5-10W before sounding scrubby. I have heard a ribbon speaker, like the Scintilla, need a vintage Krell amp to no distort.
The TA ribbon speaker uses very strong nedynium magnets, if I come 2 inches away from it anything metallic is drawn into it. But 8 inches away seem overkill! That is so strong it probably could cause health issues.
I would go at it with a dremel tool and be sure to tape over the magnetic gap. And later run tape into the magnet gap to remove particles. I bought a EL84 with a similar moisture issue. I used the dremel tool on every tube pin in the amp, and I got rid of a lot of noise.
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I meant to go at the rusty old JA6681B with a dremel tool. Not the SA ribbon speaker.
You should try to make a pure aluminum ribbon for the SA speaker and see if you reach higher clarity. I bet you would. You just need to fold kitchen foil in one of those folding roller tools, and keep the width 1 mm away from the magnet. Fix some kind of attachment at both ends/poles. Then you need a 0.5 ohm graphite resistor made of a pen, solder, a paper clip (and a straw) - or a ribbon speaker transformer (which is harder to find) - together with a powerful amp to withstand the 0.5 ohm resistance.
DIY Graphite resistors: http://www.troelsgravesen.dk/graphite.htm
I am curious how a true ribbon would sound in such a strong magnetic field. I guess the answer is RAAL.
You should try to make a pure aluminum ribbon for the SA speaker and see if you reach higher clarity. I bet you would. You just need to fold kitchen foil in one of those folding roller tools, and keep the width 1 mm away from the magnet. Fix some kind of attachment at both ends/poles. Then you need a 0.5 ohm graphite resistor made of a pen, solder, a paper clip (and a straw) - or a ribbon speaker transformer (which is harder to find) - together with a powerful amp to withstand the 0.5 ohm resistance.
DIY Graphite resistors: http://www.troelsgravesen.dk/graphite.htm
I am curious how a true ribbon would sound in such a strong magnetic field. I guess the answer is RAAL.
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I read you have covered a lot more of this topic in this thread: http://www.diyaudio.com/forums/plan...w-make-good-transformer-ribbon-tweeter-2.html
I would like to experiment with other xfmr transformers, to make the ribbon work with a tube amp. Seem very complicated tho. Maybe RAAL will sell me one separate.
I would like to experiment with other xfmr transformers, to make the ribbon work with a tube amp. Seem very complicated tho. Maybe RAAL will sell me one separate.
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